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In this work, stacked SiC fibers paper‐reinforced SiC ceramic matrix composites (SiCnf/SiC CMCs) were prepared by nanoimpregnation and transient eutectic (NITE) process using ultra‐long single‐crystal SiC nanofibers. The effect of the SiCnf surface modification via boron nitride (BN) interphase deposition as well as the sintering additive (Al2O3–Y2O3) content on the density, microstructure, and mechanical properties of SiCnf/SiC CMCs has been investigated systematically. The results revealed that the laminated SiCnf/SiC CMCs feature a significant saw‐tooth‐like curve on the load–displacement test, which indicates that the obtained laminated structure with the weak interlayer binding owning to the BN coating treatment possesses significant toughening to the SiC ceramics. Specifically, the SiCnf/SiC CMCs with the sintering additive content of 12 wt% revealed a fracture toughness of over 10 MPa m1/2 after 60 min of BN interface deposition, which is 104.31% higher than that of the composites prepared without BN coating. [ABSTRACT FROM AUTHOR]

In this work high strength and tough metal‐ceramic laminated composites are fabricated by spark plasma sintering (SPS) of Ti3Al(Si)C2 MAX‐phase filled preceramic papers (TAC) and ductile Nb foils. The sintering is carried out at 1250 °C and 50 MPa for 5–20 min. Various stacking techniques are used to obtain Nb/TAC laminated composites with different architectures. SPS results in the formation of reaction layer (RL) with a complex composition, which changes the thickness insignificantly with increasing sintering time. The possible formation mechanism of RL is discussed. The bending strength of Nb/TAC composites is decreased from 410 to 350 MPa when lowering the thickness of ceramic layer. The maximum fracture toughness of 10.2 MPa·m1/2 is achieved for the composite with similar individual layers thickness. The toughening is explained by complex fracture mechanisms associated with deflection and branching of cracks at interfaces, delamination, plastic deformation of Nb layers, multiple cracking and crack deflection in ceramic TAC layers. [ABSTRACT FROM AUTHOR]

Alumina is the most widely used oxide ceramic, and its applications are widespread in engineering and in biomedical fields. Its spheroidization was performed by a prototypal direct current (DC) thermal plasma, which was designed and installed at ENEA, investigating surface morphology, particle size distribution, crystallinity, spheroidization, and reactivity. Features such as morphology and porosity significantly influence the flowability of the powder on the printer bed and, consequently, the density of the printed parts. It has been reported that spherical powder shape is highly recommended in additive manufacturing (AM) due to its superior flowability compared to other shapes whose interaction between powder particles results in poor flowability. In this paper, the spheroidization process of alumina powders using two different DC plasma powers and two kinds of secondary gas is reported. The average value of the circularity of the powders, after plasma treatment, has always been greater than or equal to 0.8 with the degree of the spheroidization over 90% at high power. The best process parameters of the thermal plasma were properly selected to produce spherical powders suitable for AM applications, and powders with high circularity were successfully obtained. Forming, debinding, and sintering tests were performed to verify the processability and the densification of produced powders, with good results in terms of density (97%). [ABSTRACT FROM AUTHOR]

The basic material used for tools for machining wood and wood-based materials is WC-Co (Tungsten Carbide with Cobalt)-cemented carbide. The advantages of WC-Co carbides are significant resistance to high temperatures, high hardness, and wear resistance. Wood-based materials, such as particleboard, are particularly difficult to machine due to their considerable inhomogeneity and the presence of various types of hard particle inclusions, such as sand. In addition, unlike metals, wood has a low thermal conductivity, which means that most of the heat generated during milling is transferred to the tool. The consequence of this phenomenon is an increased tool temperature. In addition, the use of a coolant is not possible when machining wood-based materials. The durability of carbide blades is mainly influenced by grain size and cobalt content. When analysing WC-Co as a tool material, it is necessary to consider how it is obtained, as this can also significantly affect its properties. This paper presents the results of a durability study of cutting blades produced by the innovative Upgraded Field-Assisted Sintering Technology (U-FAST) sintering method during particleboard milling. The wear of the blades was measured until the wear value, i.e., the maximum loss at the contact surface VBmax, was 0.2 mm. Three groups of WC-Co carbides with different WC grain sizes were tested: 0.1, 0.4, and 0.8 µm. Three rotational speeds were used: 12,000, 15,000, and 18,000 rpm. In the machinability tests, blades with a WC grain size of 0.8 µm showed a twofold increase in tool life compared to commercial blades with a similar grain size gradation. [ABSTRACT FROM AUTHOR]

Compared with conventional solders, nano-silver benefits low-temperature sintering and high-temperature service, perfectly matching the high-temperature operating environment for third-generation semiconductor devices. However, the synthetic cost, complexity of the sintering process and the low connection strength limit its development. This paper describes the physical, chemical reduction and biological methods of synthesizing and compares the advantages and disadvantages of these three methods. The process parameters affecting the sintering process of silver nanoparticles (Ag NPs) are presented in a comprehensive and in-depth manner. Present methods are also introduced to improve the quality of nano-silver joints, such as the adding enhancement, the silver nanostructured films, and a trimodal-Ag paste consisting of silver particles in three sizes: nano, submicron and micron, aiming to break the limitation of the poor quality of nano-silver joints. In addition, this paper provides the first comprehensive summary of the sintering process and sintering mechanism of nano-silver, and introduces the latest results of the study of the sintering mechanism of nano-silver by using the Molecular Dynamics Simulation (MDS) technique. At the end, the advanced applications of nano-silver are shown, thus pointing out the direction for the further development and applications of nano-silver. [ABSTRACT FROM AUTHOR]

This paper aims to analyze Zr-Er sintered compounds obtained through powder metallurgy, with different concentrations, able to store H2. To obtain Zr-Er sintered compacts, in the first phase, zirconium and erbium were hydrides separately, at 750°C in a hydrogen atmosphere, for two hours each, to obtain zirconium and erbium hydrides. Using XRD analysis, both zirconium and erbium formed ErH3 and ZrH2. After the mechanical processing, morphological analysis performed by scanning electron microscopy and energy dispersive X-ray spectroscopy (SEM-EDS) revealed microparticles with sizes ranging from 8.08 µm to 27.16 µm for ZrH2, 3.72 µm to 17.86 µm for ErH3. The mixtures of hydride powders were pressed in a cylindrical mold, and two ZrxEr1-x(x=0.25;0.75) pressed compacts were obtained. These samples were subjected to a heat treatment, in a helium atmosphere, that included a dehydrogenation treatment, followed by a sintering treatment, at 1200°C, for two hours. The compounds obtained were geometrically characterized, their experimentally determined density being more than 90% of their calculated density. SEM analysis of the sintered compounds revealed a densification of zirconium and erbium particles, and also, the higher the zirconium content, the more pores the sintered sample has. SEM-EDS microstructural analysis shows a uniform distribution of the component elements, and an increased tendency of erbium to oxidize. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) methods are widely used to produce metal products. However, the cost of equipment for processes based on material melting is high. In this paper, a promising, less expensive method of producing metal products from metal-filled Ultrafuse 316L filament by FDM was investigated. The aim of this work was to compare the debinding methods and investigate the microstructure, phase composition, and geometric and mechanical properties. The results showed that catalytic debinding can be replaced by thermal debinding as no significant effect on the structure and properties was found. In addition, a filament study was performed and data on the particle size distribution, morphology, and phase composition of the metal particles were obtained. Thermodynamic modeling was performed to better understand the phase distribution at the sintering stage. The δ-Fe fraction influencing the corrosion properties of the material was estimated. The conformity of geometric dimensions to the original 3D models was evaluated using 3D scanning. The applied printing and post-processing parameters allowed us to obtain a density of 98%. The material and technology represent a promising direction for applications in the field of lightweight engineering in the manufacturing of parts with bioinspired designs, shells, and sparse filler structures with useful porosity designs (like helicoidal structures). [ABSTRACT FROM AUTHOR]

Novel alloys and advanced manufacturing methods may improve titanium-based materials' mechanical, corrosion, and biocompatibility properties. Specifically, the Ti13Nb13Zr alloy has recently garnered significant attention for orthopaedic applications, where adequate wear resistance is essential. The present paper aims to reveal dry sliding wear behaviour of the Ti13Nb13Zr alloy produced via pressure-assisted sintering. Ti13Nb13Zr samples were tested under different loads (10, 15, and 20 N) in a ball-on-disc dry sliding test system. The coefficient of friction (CoF) curves obtained to demonstrate dry sliding wear behaviour of the alloy, and the worn surface morphologies were examined to understand the underlying wear mechanisms. The mean coefficient of friction (CoF) values (and standard deviations) for the specimens subjected to increasing loads were 0.445 (0.0182), 0.480 (0.0205), and 0.465 (0.0167), respectively. Furthermore, the specific wear rates after wear were also found to be 3.76x10-3, 4.24x10-3, and 4.5x10-3 in the same order. Histogram analyses and weight loss values indicate that the 20 N test load exhibited the highest wear rate. The surface morphology was characterised by scanning electron microscopy, and energy dispersive X-ray spectroscopy (EDS) investigations were conducted. The formation of grooves and scratches was attributed to abrasive wear. The occurrence of wear debris at loads of 15 and 20 N resulted in the development of a three-body wear mechanism. Moreover, elemental mapping analysis demonstrated that the transfer of alumina ball particles on the worn surface at higher loads. [ABSTRACT FROM AUTHOR]

The Al-Si alloy prepared by the traditional powder metallurgy method has the problems of difficult sintering and low mechanical properties. In this paper, rotary extrusion combined with rapid solidification/powder metallurgy technology (RS/PM) is proposed and designed to produce an Al-10Si alloy. In subsequent sintering at different temperatures, better metallurgical bonding between particles can be achieved to fulfil the aim of improving the mechanical properties of the material. Additionally, the continuous preparation of materials can be achieved. Finally, it is verified that the density of the Al-10Si alloy sintered at 525 °C is 2.61 g/cm3, reaching 97.0% of the theoretical density, and the tensile strength reaches 336 MPa, which is much higher than that of the alloy prepared by the traditional casting method and powder metallurgy method. [ABSTRACT FROM AUTHOR]

ZrB2 with excellent high-temperature properties is used as ultra-high-temperature materials. How to synthesize ZrB2 powder with high purity and excellent properties is a key issue. In this paper, ZrB2 powder is synthesized in a vacuum by Boronthermal and Carbothermal reduction. Based on the thermodynamic calculation, the reaction process of Boronthermal and Carbothermal reduction is analyzed. The effect of reaction temperature and different raw materials ratios on the synthetic ZrB2 powder is studied by XRD. The results show that different raw materials ratio has little effect on the reduction product and reaction temperature has a great effect on it. The synthetic ZrB2 powder at 1600 °C has good properties. The synthetic ZrB2 powder with different raw materials ratio at 1600 °C is pressed into a film and sintered at 1800 °C. The phase and microstructure are studied by XRD and SEM. The results show that the synthetic powders with B4C and C powder excess 10% and 30% have good properties. [ABSTRACT FROM AUTHOR]

As the metal additive manufacturing (AM) field evolves with an increasing demand for highly complex and customizable products, there is a critical need to close the gap in productivity between metal AM and traditional manufacturing (TM) processes such as continuous casting, machining, etc., designed for mass production. This paper presents the development of the scalable and expeditious additive manufacturing (SEAM) process, which hybridizes binder jet printing and stereolithography principles, and capitalizes on their advantages to improve productivity. The proposed SEAM process was applied to stainless steel 420 (SS420) and the processing conditions (green part printing, debinding, and sintering) were optimized. Finally, an SS420 turbine fabricated using these conditions successfully reached a relative density of 99.7%. The SEAM process is not only suitable for a high-volume production environment but is also capable of fabricating components with excellent accuracy and resolution. Once fully developed, the process is well-suited to bridge the productivity gap between metal AM and TM processes, making it an attractive candidate for further development and future commercialization as a feasible solution to high-volume production AM. [ABSTRACT FROM AUTHOR]

Purpose: Material extrusion (ME) is a low-cost additive manufacturing (AM) technique that is capable of producing metallic components using desktop 3D printers through a three-step printing, debinding and sintering process to obtain fully dense metallic parts. However, research on ME AM, specifically fused filament fabrication (FFF) of 316L SS, has mainly focused on improving densification and mechanical properties during the post-printing stage; sintering parameters. Therefore, this study aims to investigate the effect of varying processing parameters during the initial printing stage, specifically nozzle temperatures, Tn (190°C–300°C) on the relative density, porosity, microstructures and microhardness of FFF 3D printed 316L SS. Design/methodology/approach: Cube samples (25 x 25 x 25 mm) are printed via a low-cost Artillery Sidewinder X1 3D printer using a 316L SS filament comprising of metal-polymer binder mix by varying nozzle temperatures from 190 to 300°C. All samples are subjected to thermal debinding and sintering processes. The relative density of the sintered parts is determined based on the Archimedes Principle. Microscopy and analytical methods are conducted to evaluate the microstructures and phase compositions. Vickers microhardness (HV) measurements are used to assess the mechanical property. Finally, the correlation between relative density, microstructures and hardness is also reported. Findings: The results from this study suggest a suitable temperature range of 195°C–205°C for the successful printing of 316L SS green parts with high dimensional accuracy. On the other hand, Tn = 200°C yields the highest relative density (97.6%) and highest hardness (292HV) in the sintered part, owing to the lowest porosity content (<3%) and the combination of the finest average grain size (∼47 µm) and the presence of Cr23C6 precipitates. However, increasing Tn = 205°C results in increased porosity percentage and grain coarsening, thereby reducing the HV values. Overall, these outcomes suggest that the microstructures and properties of sintered 316L SS parts fabricated by FFF AM could be significantly influenced even by adjusting the processing parameters during the initial printing stage only. Originality/value: This paper addresses the gap by investigating the impact of initial FFF 3D printing parameters, particularly nozzle temperature, on the microstructures and physical characteristics of sintered FFF 316L SS parts. This study provides an understanding of the correlation between nozzle temperature and various factors such as dimensional integrity, densification level, microstructure and hardness of the fabricated parts. [ABSTRACT FROM AUTHOR]

This work analyzes the energy performance implications of the physicochemical properties and the mineralogical elemental composition of agro-industrial wastes in the form of pellets (ISR pellets) and pine bark chips (PBCh). ISR pellets were made from a mixture of industrial wastewater treatment plant (IWTP) primary sludge, coal boiler ashes (CBA), and wood waste chips (WW), which are wastes rich in inorganic material and with a usable energy potential. All these residues were obtained from the production processes of paper company (Smurfit Kappa Colombia). ISR pellets and PBCh were tested as individual and mixed fuels in the thermochemical gasification and combustion processes. Several synergistic effects were found through the co-processing of these fuels, resulting in improvements in the performance indices normally used for the energy assessment of waste, as well as substantial environmental impact and operational behavior improvements. These effects were predicted through fusibility correlations from the elemental composition of the inorganic content, particularly the low melting point salts precursor species and fusibility temperature, as developed for coal ashes. The results of experimental co-processing validated these predictions. [ABSTRACT FROM AUTHOR]

In this paper, alumina-reinforced copper-based composite materials were prepared by using the electroless plating method to coat copper powder with a layer of silver and then combining the solution sol method and powder metallurgy method. The results show that recrystallized structures and twins appear in composite materials after high-temperature sintering. As the sintering temperature increases, the ratio of recrystallized structures and twins gradually decreases, and straight coherent Σ 3 annealing twins appear in the structure, the number of high-angle grain boundaries decreased, the number of small-angle grain boundaries continues to increase, the average grain size increased from 3.89 to 4.83 μ m, the tensile strength increased from 156 MPa to 167.5 MPa, the maximum elongation was 9.4%, and the density increased from 6.81 g/cm3 increased to 7.62 g/cm3, the porosity dropped from 13.3% to 5.5%, the conductivity increased from 60.3% IACS to 73.2% IACS, the maximum hardness value was 68.71 HV, the best performance of the composite was achieved by sintering at 900°C with the tensile strength and elongation are 163 MPa and 9%, respectively, the conductivity is 68.9% IACS, and the density is 7.35 g/cm3. Its fracture surface shows mostly ductile features. [ABSTRACT FROM AUTHOR]

CuCr alloy has become the preferred contact material in the field of environmental protection vacuum switches because of its good mechanical and electrical properties, and the development of preparation technology of highly dense and homogeneous CuCr alloy has become one of its research directions. In this paper, the concepts of liquid phase sintering and complementary copper infiltration are coupled to prepare CuCr50 alloys, which are subjected to secondary treatment using solid solution as well as aging heat treatments, to observe the evolution of the microstructure and properties of CuCr50 alloys. It is found that CuCr50 alloy can be prepared stably by liquid phase sintering coupled with complementary copper infiltration. The average particle size of the Cr-rich phase in CuCr50 alloy is 48.9 μm after liquid phase sintering, solid solution treatment and aging treatment, and the uniformity of the distribution of the Cr-rich phase is improved compared with the billet and sintered state. At this time, the density of the CuCr50 alloy is 7.94 g·cm−3, the electrical conductivity is 22.77 MS·m−1, and the hardness reaches 113.2 HB. Compared with the requirements in the national standard GB/T 26867-2011, the density, conductivity, and hardness are increased by 0.51%, 42.3%, and 41.5%, respectively. The peak of the density of states at energies around −5 eV on the total density of states diagram is contributed by the superposition of the 3d orbitals of Cu and the 3d orbitals of Cr, which is a reason for the stable existence of the CuCr50 alloy. [ABSTRACT FROM AUTHOR]

Thermokinetic features of phase formation during the synthesis of new materials are of considerable interest for the construction of models and optimization of powder technologies. The aim of this work was to investigate possible mechanisms of phase formation in the Ti–CuO system under conditions of volumetric heating. The main reactions possible in the system were analyzed, a kinetic model was proposed, and its parameters were calculated on the basis of thermodynamic data and semi-empirical theories. An algorithm for the numerical study of the kinetic model using a time step that adapts to the changes in composition is proposed. A kinetic scheme is used to construct a simple sintering model for different temperature regimes. Experimental data on reactive sintering in a vacuum chamber and under conditions leading to thermal explosion upon heating are presented. The analysis of the results allowed us to significantly supplement the preliminary model with chemical stages leading to the nonequilibrium composition of the synthesis products observed in the experiment. Possible kinetic difficulties contributing to the nonequilibrium composition are described. [ABSTRACT FROM AUTHOR]

During the sintering process in iron production, wheel swing is a sign of sintering machine trolley axle faults, which may lead to the wheel falling off and affect the production operation of the sintering machine system in serious cases. To solve this problem, this paper proposes a fault detection and localization method based on the You Only Look Once version 9 (YOLOv9) object detection algorithm and frame difference method for detecting sintering machine trolley wheel swing. The wheel images transmitted from the camera were sent to a trolley wheel and side panel number detection model that was trained on YOLOv9 for recognition. The wheel recognition boxes of the previous and subsequent frames were fused into the wheel region of interest. In the wheel region of interest, the difference operation was carried out. The result of the difference operation was compared with the preset threshold to determine whether the trolley wheel swings. When a wheel swing fault occurs, the image of the side plate at the time of the fault is collected, and the number on the side plate is identified so as to accurately locate the faulty trolley and to assist the field personnel in troubleshooting the fault. The experimental results show that this method can detect wheel swing faults in the industrial field, and the detection accuracy of wheel swing faults was 93.33%. The trolley side plate numbers' average precision was 99.2% in fault localization. Utilizing the aforementioned method to construct a system for detecting wheel swing can provide technical support for fault detection of the trolley axle on the sintering machine. [ABSTRACT FROM AUTHOR]

Purpose: Modification of sintered iron with the addition of molybdenum and boron leads to the formation of boride phases that significantly impact the properties of the sintered materials. The paper aims to determine Fe-Mo-B phases that might be formed during the sintering of base powders. With EDS microanalysis, determining those phases in the microstructure is difficult since the B-Kα peak is extremely close to Mo-Mζ (only a 9.3 eV difference). Thus, diffraction techniques must be implemented to unambiguously define the phases occurring in the sintered samples (WDS and EBSD). Design/methodology/approach: The sintered samples were obtained from initial powders of Fe, Mo, and B that were mixed and compressed. The reducing hydrogen atmosphere was used to sinter green samples at 1200°C for 60 minutes. The obtained sinters were subjected to microstructural observations by scanning electron microscope, and some analyses (EDS/WDS and EBSD) were conducted, which led to the determination of phases present in the material. Findings: Based on the investigations conducted, iron, molybdenum, and molybdenumiron borides have been reported. It is confirmed with the EBSD method that Fe2B, MoB and FeMo2B2 phases are formed in particles' connection regions. Besides, the interparticle region, formed due to a liquid phase during sintering, is based on Fe-Fe2B eutectic. The microstructural observations prove that the amount of the liquid phase, and thus the size of the interparticle region, diminishes with increasing molybdenum content. It was also noted that the iron matrix (interior of former iron particles) is free from contributing elements coming from boron or molybdenum powders. Research limitations/implications: The application of the EDS method is limited in the case of measuring boron in Mo-containing alloys and phases. The EDS method does not have a sufficient energetic resolution to separate the B-Kα line from Mo-Mζ one. Thus, it must be complemented with WDS and EBSD in order to unambiguously determine the presence and localization of iron and molybdenum borides. Practical implications: It can be stated that WDS has sufficient energy resolution to separate B-Kα from Mo-Mζ emission lines. Therefore, WDS analysis is suitable for boride observation in sintered iron powders by constructing distribution maps of interparticle connection regions and precipitates. Besides, measurements by the EBSD method can be used to confirm the presence of Fe2B, MoB and FeMo2B2 phases. Originality/value: Determination of boron-containing phases in Fe-Mo-B sinters by means of diffraction methods. [ABSTRACT FROM AUTHOR]

In kraft paper mills, supersonic steam jets are used to remove deposits that build up on the heat exchanger tubes in the recovery boiler. In this study, the fracture toughness KC and work of fracture, WF, of simulated boiler deposits were measured at temperatures up to 500 °C to determine the optimal conditions for deposit removal. The model deposits experienced an important brittle to ductile transition at ~450 °C. Above this temperature, ductile deposits required lower peak force, but four times more energy to fracture when compared to those tested at lower temperatures. The transition was clear in scanning electron micrographs of the fracture surfaces. The findings have significant implications for mills wishing to optimize sootblower performance. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A non-firing solidification method using surface-activated ceramic powders with mechanochemical treatment and solidified without a high-temperature sintering process has been studied in our group. In this method, the surfaces of ceramic particles are activated by grinding, and this activated state is used as a driving force to bond the particles together. It is essential to computationally understand the mechanical activation and solidification processes in the non-firing process at various molecular and bulk scales. This paper first outlines the differences between the non-firing solidification process and the conventional sintering process. Next, we introduce our simulation results of the non-firing solidification process and discuss future prospects. [ABSTRACT FROM AUTHOR]

It is expected that composites made of carbon nanotubes (CNT) and copper (Cu) display both mechanical and electrical properties, but the low damage dispersion and high-quality composite of high-content CNTs have always been research difficulties. In this paper, high-content CNTs/Cu composites were prepared. The effects of the sintering method, sintering temperature, directional rolling and the CNTs' content on the relative density, hardness and electrical conductivity of the composites were studied. The uniform dispersion of high-content CNTs in Cu matrix was achieved by ball milling, sintering and rolling, and the processes did not cause more damage to the CNTs. The properties of composites prepared by spark plasma sintering (SPS) and vacuum hot pressing sintering (HPS) were compared, and the optimum process parameters of SPS were determined. When the CNTs' content is 2 wt.%, the hardness is 134.9 HBW, which is still 2.3 times that of pure Cu, and the conductivity is the highest, reaching 78.4%IACS. This study provides an important reference for the high-quality preparation and performance evaluation of high-content CNTs/Cu composites. [ABSTRACT FROM AUTHOR]

This paper reports the pressureless sintering behavior and the activation energy of the powdered MAX phases Ti3SiC2 and Ti2AlC. A non-isothermal technique was used to determine the sintering kinetic parameter. The Ti3SiC2 and Ti2AlC MAX phases showed the maximum sintering rate at 1723 K, 0.14 and 0.10 µm/s, respectively. The sintering rate of the sample at different temperatures followed a cubic equation which was determined. The sintering activation energy (Ea) for the Ti3SiC2 and Ti2AlC samples was 362.1 kJ/mol and 640.3 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

With substantial advancements in the additive manufacturing (AM) of polymers and metals in the last few decades, the AM of ceramic material has recently gained research traction. Manufacturing complex ceramic parts is an extremely challenging process that can be revolutionized by AM. While many industrial-grade expensive AM systems are available for printing ceramic parts, the use of inexpensive desktop-type extrusion AM systems for ceramic parts is particularly challenging, which mandates printing parameter optimization. In this paper, the printing parameters of an inexpensive extrusion AM system, such as layer height, line width, extrusion speed, infill, and flow percentage, were optimized, which resulted in ceramic parts with desired qualities in terms of part density. For this, Clay Body 370 was chosen to produce clay with different percentages of water content ranging from 5% to 15%. Printed samples were subjected to sintering in a furnace to sinter at 1100 °C, followed by shrinkage and weight loss measurements. Finally, the printing parameters that resulted in good surface quality and less dimensional shrinkage with higher compression strength were reported. [ABSTRACT FROM AUTHOR]

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The quality of sintered ore, which serves as the primary raw material for blast furnace ironmaking, is directly influenced by the moisture in the sintering mixture. In order to improve the precision of water addition in the sintering process, this paper proposes an intelligent model for predicting water-filling volume based on Temporal Fusion Transformer (TFT), whose symmetry enables it to effectively capture long-term dependencies in time series data. Utilizing historical sintering data to develop a prediction model for the amount of mixing and water addition, the results indicate that the TFT model can achieve the R squared of 0.9881, and the root mean square error (RMSE) of 3.5951. When compared to the transformer, long short-term memory (LSTM), and particle swarm optimization–long short-term memory (PSO-LSTM), it is evident that the TFT model outperforms the other models, improving the RMSE by 8.5403, 6.9852, and 0.453, respectively. As an application, the TFT model provides an effective interval reference for moisture control in normal sintering processes, which ensures that the error is within 1 t. [ABSTRACT FROM AUTHOR]

In this paper, two new ternary layered MAX phase ceramics, Sc2GaC and Sc2InC, were successfully synthesized by spark plasma sintering. The crystal structures of two new compounds were determined by X‐ray diffraction. The lattice parameters were a = 3.3609(0) Å and c = 14.5849(9) Å for Sc2GaC, and a = 3.3453(6) Å and c = 15.2236(3) Å for Sc2InC, wherein the Sc atoms were located at (1/3, 2/3, 0.07330[Ga]/0.08268[In]), the A atoms were located at (1/3, 2/3, 3/4), and the C atoms were located at (0, 0, 0). Scanning electron microscopy images of two new MAX phase ceramics were also given in this paper, showing obvious layered characteristics. [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental studies on the production of hafnium carbide powder by the atmospheric arc technique and the use of the synthesis product for sintering a bulk ceramic sample. X-ray phase analysis and scanning electron microscopy of the synthesis product and the bulk ceramic sample have been carried out. It has been shown that after consolidation, the bulk ceramic sample has a density of 99.1% and a hardness of 17 GPa. [ABSTRACT FROM AUTHOR]

Paper-related production of composite materials from Al2O3-pre-composite powder (NiAl–10 wt pct Al2O3). PPS allowed for forming ceramic–intermetallic composites. MA produced the pre-composite powder. Six series of composites were made, differing in temperature (1200 °C, 1300 °C, 1400 °C) and content of pre-composite powder (2.5 and 5 wt pct with respect to the amount of Al2O3). Highest hardness was obtained for composite series sintered at 1300 °C. Both series, with various pre-composite powder content, had a value of 20.8 to 20.9 GPa. Samples containing 2.5 wt pct pre-composite powder sintered at 1200 °C were highest KIC value of 4.72 ± 0.34 MPa·m0.5. Interestingly, the same value was obtained in composites containing 5 wt pct pre-composite powder sintered at 1300 °C. For both series with different pre-composite powder content, sintering at 1400 °C obtained the highest strength. For composites containing 2.5 wt pct pre-composite powder, splitting tensile strength value was 255.98 MPa, while for samples with 5 wt pct, pre-composite powder was 264.01 MPa [ABSTRACT FROM AUTHOR]

Non-firing functional oxide materials are attracting significant interest due to their suitability for a wide range of applications, particularly in thermal, electrical, and architectural fields. These materials, which range from natural to synthetic forms, offer a diverse range of properties. While oxides are generally known for their high mechanical strength, temperature resistance, and cost-effectiveness, traditional oxide processing often requires energy-intensive and environmentally unfriendly high-temperature sintering. Therefore, the investigation of energy-efficient non-firing mechanisms for oxides is not only beneficial but crucial. This paper reviews the advancements in non-firing mechanisms, with a focus on material selection, synthesis processes, and potential applications. Special attention is given to non-firing forms such as silica-based and geopolymer materials, which are prepared using low-energy acid-base reactions with either natural or synthetic silica-alumina sources. The review also encapsulates the challenges and solutions associated with these sustainable, non-firing oxide materials. [ABSTRACT FROM AUTHOR]

Y2O3 transparent ceramics have broad applications including solid-state lasers, transparent windows, etc., owing to its excellent optical and physical-chemical properties. The dispersity of the powder among the fabrication process of transparent ceramics has attracted much attention from researchers for decades. In this paper, domestic commercial nanopowder was adopted as the starting material, and the dispersion of the powder was improved through mechanical force combined with HF acid-washing. Y2O3 transparent ceramics with high transmittance were achieved by slip casting and vacuum sintering. The results show that ultrasonic combined with HF acid-washing is an effective way to improve the dispersibility and sinterability of the powder, the D50 of the powder reduces from 3. 5 µm to 1. 4 µm. The transmittance of the Y2 O3 ceramic at 400 nm is improved from 65. 5% to 71. 5% for the sample after ultrasonic combined with HF acid-washing process. The results lay a solid foundation of preparation technology and theoretical basis for the application of Y2 O3 transparent ceramics on solid-state lasers and transparent window materials. [ABSTRACT FROM AUTHOR]

Spinel-type Zn1.1 Ga1.8 Ge0.1 O4 is an excellent host material for dielectric and long-persistent luminescent ceramics. It is helpful to expand application when the transparent ceramics is fabricated. In this paper, the pressureless sintering kinetics of Zn1.1 Ga1.8 Ge0.1 O4 ceramics were studied. The results show that both densification and grain growth are controlled by the grain boundary diffusion of O2- . The activation energy for densification in the intermediate sintering stage is determined as (426 ±35) kJ/mol, while the activation energy' for grain growth in the final sintering stage is calculated as (439 ±14) kJ/mol. When the combination of sintering parameters is optimized to enter into the so-called "sintering window", the favorable microstructure of the pressureless-sintered body is obtained. After hot isostatic pressed at high temperature, Zn1.1 Ga1.8 Ge0.1 O4 transparent ceramics with optical transmission ranging from 0. 3µm to 9 µm and in-line transmittance of 81. 2% at 2. 5µm are prepared. [ABSTRACT FROM AUTHOR]

As a typical garnet transparent ceramic used in high-energy solid-state laser systems, terbium aluminum garnet (Tb3Al5O12, TAG) magneto-optic ceramics have become a focal point of research due to their excellent magneto-optic properties and high-power performance. This paper focuses on TAG magneto-optic ceramics prepared by vacuum solid-state reaction, with particular emphasis on the optimization of sintering aids and lattice doping modifications. By comparison, the most suitable additives for TAG ceramics were identified. The study highlights the longstanding challenge in improving the quality of TAG ceramics, which arises from the reliance on large doses of sintering aids and the resulting compositional inhomogeneity caused by sintering aid residues. To address these issues, we present our latest research, which involves co-doping the lattice with Mg2+ and Si4+. This approach enables the preparation of higher optical quality TAG ceramics via a one-step vacuum solid-state sintering process, without reducing the absolute amount of MgO and TEOS. The best sample achieve a transmittance of 82.48% at 1 064 nm, which, to our knowledge, is the highest value reported using a similar sintering method based on domestic powders. This lattice doping strategy, rather than the traditional mass-ratio addition of sintering aids, offers a promising new approach for further improving the quality of garnet transparent ceramics used in high-energy laser systems. [ABSTRACT FROM AUTHOR]

The paper provides experimental results of obtaining high-density ZrO2+3%Y2O3 ceramics, which is promising for use as a matrix for immobilization of HLW. The effect of sintering temperature in the range of 1100...1650 °C on the microstructure of the sintered tablets was studied. Phase composition and microstructure of experimental samples were characterized by XRD and SEM. Grain size distribution analysis was carried out using the "Thixomet" image analyzer. Microhardness was determined using a metallographic complex LECO (USA), an inverted microscope IM-3MET and a hardness tester UIT HVB-30. It was established that increase in the sintering temperature leads to a significant increase in the average grain size (from 85 nm to 1000 nm) and increase in the density of the sintered tablets. Sintering temperature should be at least 1550...1650ºС to produce high-dense ceramics (97...98 % of theoretical value). Obtained ceramics is characterized by high values of microhardness HV > 12 GPa and crack resistance of 5.5...6.3 MPa·m1/2. [ABSTRACT FROM AUTHOR]

In this paper, a "multi-thin foil" structure + "two-stage" reaction strategy was employed to prepare B2-FeAl based MIL composite, and the effects of two different processes: conventional low-temperature hot-press sintering (CLT-HP) and fast high-temperature hot-press sintering (FHT-HP) on microstructure and mechanical properties were investigated. The results show that the MIL composites prepared by the two processes both exhibit multi-layer structure consisting of residual stainless steel layer, newly formed intermetallic layer, and intermediate transition layer. The metal layer is composed of both α-Fe and γ-Fe phases for CLT-HP, but only γ-Fe phase for FHT-HP counterpart. The intermetallic layer and transition layer mainly contain B2-FeAl phase for the two processes. Interestingly, multiple-sublayer structure was formed in the intermetallic layer and its thickness is obviously smaller and uniform for CLT-HP than FHT-HP. A kinetics calculation based on one-dimension diffusion equation was conducted to model the growth of B2-FeAl intermetallic layer, which exhibits a good consistency with the experimental results in terms of reaction rate and concentration profiles. CLT-HP MIL composites have better comprehensive mechanical properties than FHT-HP counterpart, especially for the compressive strength in the direction parallel to the layers, which is approximately 1 GPa higher for the former than the latter. This is mainly attributed to a good transitional role in properties through the transition layer and multiple-crack fracture mechanism in the intermetallic layer for CLT-HP MIL composite. [ABSTRACT FROM AUTHOR]

Abstract: Paper electronics is considered very environmentally friendly, but effective recyclability of metallic circuits on paper still needs more improvement. Therefore, liquid metal (Galinstan) circuits based on the reversible conversion from particles to wires are fabricated on paper using mechanical methods, i.e., mechanical sintering and sonication. Line‐width of liquid metal (LM) circuit is kept in the range of 10 µm to ≥0.5 mm by controlling the sintering force. The results demonstrate that LM circuits exhibit high electrical stability during deformation, as resistance changes only ≤4% after the passage of 10 000 folding cycles. Meanwhile, LM particles spread on paper's porous structures, have enhanced the thermal diffusivity of paper and make paper electronics work in a facile temperature when integrated with high density units. More importantly, the reborn circuits exhibit almost identical electrical stability under deformation and thermal characteristic with pristine ones, thus making LM circuits environmentally friendly during their whole life span. [ABSTRACT FROM AUTHOR]

Novel paper‐derived Ti3SiC2‐based ceramics are fabricated by spark plasma sintering (SPS). A Ti3SiC2‐loaded preceramic article is used as feedstock. The sintering temperature and pressure are 1100–1200 °C and 20–50 MPa, respectively. The influence of sintering parameters on phase composition and microstructure is analyzed by X‐ray diffraction (XRD) and scanning electron microscopy, respectively. In addition, energy‐dispersive X‐ray spectroscopy is conducted to analyze the distribution of elements and the phase arrangement depending on the sintering temperature. XRD analysis of the composites sintered at 1100 and 1200 °C shows the presence of Ti3SiC2, TiC, and TiSi2 phases while the content of Ti3SiC2 phase decreases with increasing temperature. It is shown that an increase in both temperature and pressure lead to higher densification of the composites. Elongated pores are observed in the composites, which are formed as a result of cellulose fiber decomposition during the sintering process. The maximal value of the flexural strength of 300 MPa is measured for the composite with the highest density. The influence of SPS parameters on the formation of phase composition, microstructure, and mechanical properties of the paper‐derived Ti3SiC2‐based ceramics is discussed. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents the results of the experimental research on diamond-reinforced composites with WC–Co matrices enhanced with a ZrO2 additive. The samples were prepared using a modified spark plasma sintering method with a directly applied alternating current. The structure and performance of the basic composite 94 wt.%WC–6 wt.%Co was compared with the ones with ZrO2 added in proportions up to 10 wt.%. It was demonstrated that an increase in zirconia content contributed to the intense refinement of the phase components. The composite 25 wt.%Cdiamond–70.5 wt.%WC–4.5 wt.%Co consisted of a hexagonal WC phase with lattice parameters a = 0.2906 nm and c = 0.2837 nm, a cubic phase (a = 1.1112 nm), hexagonal graphite phase (a = 0.2464 nm, c = 0.6711 nm), as well as diamond grits. After the addition of zirconia nanopowder, the sintered composite contained structural WC and Co3W3C phases, amorphous carbon, tetragonal phase t-ZrO2 (a = 0.36019 nm, c = 0.5174 nm), and diamond grits—these structural changes, after an addition of 6 wt.% ZrO2 contributed to an increase in the fracture toughness by more than 20%, up to KIc = 16.9 ± 0.76 MPa·m0.5, with a negligible decrease in the hardness. Moreover, the composite exhibited an alteration of the destruction mechanism after the addition of zirconia, as well as enhanced forces holding the diamond grits in the matrix. [ABSTRACT FROM AUTHOR]

Screen printing enables the production of very thin magnetic sheet laminations in near net shape geometry. This minimizes material waste in production and simultaneously reduces losses during machine operation and in-creases geometric design freedom. The subsequent sintering process step is particularly relevant, since the geometrical and magnetic properties are defined, and relevant process costs are caused by the heat treatment. This paper presents the requirements of the debinding and sintering process for magnetic sheets and identifies relevant influencing factors to achieve defined product specifications in multiple iterations, using design of experiments. It focuses on the influencing factors furnace atmosphere, sintering temperature, holding time and stacking height and their impact on the magnetic and geometric properties of sintered magnetic sheets. [ABSTRACT FROM AUTHOR]

Compared with traditional powder metallurgy, pulse current sintering is an advanced powder-forming technology, but its bonding mechanism is still an open topic for debate. In this paper, pulse current sintering is used as the connection technology and millimeter-sized Al particles are used as the research object. In the whole sintering process, no pressure was loaded; the function of the pulse current was the only source of heat with which to achieve the bonding of Al particles. The bonding mechanism of pulse current sintering was investigated from the perspective of material connection behavior. The results show that the pulse current density of the particle surface reaches 3.48 × 105 A/m2 instantly, while the current density of the particle center is only 8187 A/m2 at the initial stage, which is the main difference between pulse current sintering and traditional powder metallurgy sintering. With the densification process, the current density and temperature distribution in the contact region as well as the center of Al particles contact region tend to be more consistent. Finally, dense interfacial bonding was obtained, and the contact region of Al particles also demonstrated a high hardness value of 0.6385 GPa and yield strength value of 212.83 MPa. The whole process can be considered as a comprehensive action of melting (evaporation), diffusion, and plastic deformation. Based on the above results, a new technology, named high-frequency pulse current sintering, was proposed. [ABSTRACT FROM AUTHOR]

The paper presents the influence of the temperature of the sintering process on the microstructure and selected properties of boron carbide/TiB2/SiC composites obtained in situ by spark plasma sintering (SPS). The homogeneous mixture of boron carbide and 5% vol. Ti5Si3 micropowders were used as the initial material. Spark plasma sintering was conducted at 1700 °C, 1800 °C, and 1900 °C for 10 min after the initial pressing at 35 MPa. The heating and cooling rate was 200 °C/min. The obtained boron carbide composites were subjected to density measurement, an analysis of the chemical and phase composition, microstructure examination, and dry friction-wear tests in ball-on-disc geometry using WC as a counterpart material. The phase compositions of the produced composites differed from the composition of the initial powder mixture. Instead of titanium silicide, two new phases appeared: TiB2 and SiC. The complete disappearance of Ti5Si3 was accompanied by a decrease in the boron carbide content of the stoichiometry formula B13C2 and an increase in the content of TiB2, while the SiC content was almost constant. The relative density of the obtained boron carbide composites, as well as their hardness and resistance to wear, increased with the sintering temperature and TiB2 content. Unfortunately, the reactions occurring during sintering did not allow us to obtain composites with high density and hardness. The relative density was 76–85.2% of the theoretical one, while the Vickers hardness was in the range of 4–12 GPa. The mechanism wear of boron carbide composites tested in friction contact with WC was abrasive. The volumetric wear rate (Wv) of composites decreased with increasing sintering temperature and TiB2 content. The average value of coefficient of friction (CoF) was in the range of 0.54–0.61, i.e., it did not differ significantly from the value for B4C sinters. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) has been recognized as one of the beneficial components in the electron transport layer (ETL) of lead–halide perovskite solar cells (PSCs) due to its high electron mobility. The SnO2-based thin film serves for electron extraction and transport in the device, induced by light absorption at the perovskite layer. The focus of this paper is on the heat treatment of a nanoaggregate layer of single-nanometer-scale SnO2 particles in combination with another metal-dopant precursor to develop a new process for ETL in PSCs. The combined precursor solution of Li chloride and titanium(IV) isopropoxide (TTIP) was deposited onto the SnO2 layer. We varied the heat treatment conditions of the spin-coated films comprising double layers, i.e., an Li/TTIP precursor layer and SnO2 nanoparticle layer, to understand the effects of nanoparticle interconnection via sintering and the mixing ratio of the Li-dopant on the photovoltaic performance. X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM) measurements of the sintered nanoparticles suggested that an Li-doped solid solution of SnO2 with a small amount of TiO2 nanoparticles formed via heating. Interestingly, the bandgap of the Li-doped ETL samples was estimated to be 3.45 eV, indicating a narrower bandgap as compared to that of pure SnO2. This observation also supported the formation of an SnO2/TiO2 solid solution in the ETL. The utilization of such a nanoparticulate SnO2 film in combination with an Li/TTIP precursor could offer a new approach as an alternative to conventional SnO2 electron transport layers for optimizing the performance of lead–halide perovskite solar cells. [ABSTRACT FROM AUTHOR]

This review discusses the groundbreaking advancements in electric current-assisted sintering techniques, specifically Flash Sintering (FS) and Ultrafast High-Temperature Sintering (UHS), for their application in Solid Oxide Fuel Cells (SOFCs). These innovative sintering methods have demonstrated remarkable potential in enhancing the efficiency and quality of SOFC manufacturing by significantly lowering sintering temperatures and durations, thereby mitigating energy consumption and cost. By providing a detailed overview of the mechanisms, process parameters, and material characteristics associated with FS and UHS, this paper sheds light on their pivotal role in the fabrication of SOFC components such as electrolytes, electrodes, multilayered materials, and interconnect coatings. The advantages, challenges, and prospective opportunities of these sintering technologies in propelling SOFC advancements are thoroughly assessed, underlining their transformative impact on the future of clean and efficient energy production technologies. [ABSTRACT FROM AUTHOR]

The article presents some existing methods of producing silicon carbide, forms and types of silicon carbide, various compositions and formulations, production technology. The authors proposed a new method of processing silicon production waste - microsilica by spark plasma sintering with a carbon-containing reducing agent (soot) which produces a silicon carbide compound. Studies have shown that sintered silicon carbide has improved strength properties. Thus, the possibility of application of production wastes to create new composite materials characterized by a certain complex of properties is confirmed. [ABSTRACT FROM AUTHOR]

The poor mechanical and tribological properties limit the higher requirements of aluminum alloys in engineering and industrial applications, which leads to the rapid development of aluminum matrix composites (AMCs). Particulate reinforced AMCs have attracted extensive attention in automobile, electronics and military industries due to their low density, high strength, and excellent wear resistance. However, the interfacial reaction between reinforcements and the Al matrix tends to occur in conventional preparation processes owing to the higher reaction temperatures. The spark plasma sintering (SPS) technique is considered to be an efficient method for the fabrication of metal matrix composites, which can achieve rapid sintering, lower sintering temperatures, and higher densities than conventional fabrication processes. In addition, SPS can produce AMCs with excellent non-porous microstructure, fine grain size, and a strong bonding interface between reinforcement and Al matrix. Therefore, the interfacial reaction is effectively controlled and the structural integrity is maintained, resulting in enhanced strength and ductility. Based on the advantages of particulate reinforced AMCs and the SPS technique, the particulate reinforced AMCs fabricated by SPS have been extensively studied in recent decades, but have not been systematically evaluated. Therefore, this paper reviews the state-of-the-art particulate reinforced AMCs fabricated by SPS, focusing on the microstructure characterization, strengthening mechanisms, and mechanical and physical properties. Furthermore, the future research priorities and challenges of the high-performance particulate reinforced AMCs fabricated by SPS are also prospected. [ABSTRACT FROM AUTHOR]

Copyright of Iron Steel Vanadium Titanium is the property of Iron Steel Vanadium Titanium Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, high thermal conductivity Si3N4 ceramics were successfully fabricated through exploring and optimizing the tape casting process. The impact of various organic additives on the rheological characteristics of Si3N4 slurry was explored, and the pore size distribution and microstructure of the green tapes at different solid loadings were investigated, as well as the microstructure of Si3N4 ceramics. Green tapes with a narrow pore size distribution, a small average pore size, and a high density of 1.88 g cm−3 were prepared by the investigation and optimization of the Si3N4 slurry formulation. After gas pressure sintering, Si3N4 ceramics with a density of 3.23 g cm−3, dimensions of 78 mm × 78 mm, and a thickness of 0.55 mm were obtained. The microstructure of the Si3N4 ceramics showed a bimodal distribution and a low content of glassy phases. The thermal conductivity of the Si3N4 ceramics was 100.5 W m−1 K−1, the flexural strength was 735 ± 24 MPa, and the fracture toughness was 7.17 MPa m1/2. [ABSTRACT FROM AUTHOR]

Electric field-assisted densification of Ti3SiC2 powder was investigated in this paper. A signature behavior of flash sintering experiments is that the current passing through the sample increases rapidly with increasing temperature. The conductivity of Ti3SiC2 powder is high enough to lead current to flow through the sample even at room temperature; therefore, the current reaches its maximum value as soon as an electric field is applied. On the other hand, the variation of the power can be observed as a function of time and temperature. Such response of Ti3SiC2 to an electric field can be presented as an example of flash sintering in conductive ceramic materials. The compacted Ti3SiC2 sample sintered to 93.5% of the theoretical density at 1400 °C under a 7.5 V/mm electric field and 17 mA/mm2 current density limitation. No decomposition of the phase was observed at all experiments. The microstructure of the fractured samples revealed the preservation of the laminated structure of Ti3SiC2. [ABSTRACT FROM AUTHOR]